Replies

1. 
   jszens | Oct 07, 2019 10:06pm | #1

   Not sure what the question is here. If it implies that the degree of sanding affects the level of final sheen, that is not correct: the appearance of the finished surface (satin vs. gloss) is controlled by the choice of topcoat.

   Sanding should be done as needed to remove surface imperfections which will be magnified by the finish, particularly if you're using a clear film finish like shellac, polyurethane or other varnish.

   One final thought: if you want to control the level of "satin-ness" of your piece, use a gloss finish and then knock down the gloss with very fine sandpaper or high-quality 0000 steel wool. If you use a satin finish, you get the sheen the finish gives you. In other words, you can always make a gloss finish satin, but not vice versa.

2. 
   Highdesertwoodworker | Oct 07, 2019 10:24pm | #2

   Can one make epoxy coating satin (without the gloss) with very fine sand paper or 0000 steel wool? Thanks

3. 
   Highdesertwoodworker | Oct 07, 2019 11:10pm | #3

   I am not suggesting that the final grit determines the glossiness; I am asking whether the choice of satin final coat allows one to sand to a coarse grit, say stopping at 220 grit.

4. 
   jszens | Oct 08, 2019 12:22pm | #4

   I will give you a very general, qualified answer here, because I am not familiar with the finish you're talking about.

   The general answer is: yes.

   Assuming the dried, cured finish is softer than the abrasive you're using, the abrasive will indeed create a scratch pattern on the surface of the finish. The coarser the scratches, the duller the finish will look. Very fine scratches will leave a surface closer to gloss.

   You have heard this before but it bears repeating here: try all of this out on a sample board that you've prepared exactly like the project you want to finish. Better to mess up a sample than a piece you have spent hours and hours getting ready.

5. 
   jszens | Oct 08, 2019 12:29pm | #5

   Well, 220 isn't awfully coarse, but the final grit you use won't impact the glossiness of the finish. The finish is what it is.

   If you're still referring to an epoxy finish you referenced above, the finish will flow into the scratches left by the sandpaper and level them out.

   In your mind, make a distinction between sanding and applying a film finish: Sanding prepares the wood surface and should remove all traces of surface defects (tearout, thickness planing, any little rough spots, etc.) These will be magnified by a film finish.

6. 
   Highdesertwoodworker | Oct 08, 2019 03:42pm | #6

   Say polyurethane will say either satin, semi-gloss, or gloss on the can.

7. 
   john_c2 | Oct 08, 2019 05:35pm | #7

   Are you talking about sanding the wood before any finish, or sanding the finish after it dries?

8. 
   Highdesertwoodworker | Oct 08, 2019 06:11pm | #8

   Since the purpose is to save labor and prevent veneer from wearing away, I like to know about sanding both before and after final finish.

9. 
   jszens | Oct 09, 2019 12:44pm | #9

   You are blending two operations - sanding the wood and "finishing the finish" - into one operation. These are two different operations with two different outcomes.

   The objective of sanding the wood surface is to remove defects and prepare the surface for the finish.

   The objective of using an abrasive on a finish is to level the finish, remove dust nibs, and create the sheen you are after.

10. 
    johngr2022 | Oct 09, 2019 09:54pm | #10

    The bare wood needs to be prepared for the finish by sanding (to 220 or 320 sandpaper [I use a net abrasive, Abranet, in 240/400] or by using a plane to smooth the wood. I routinely finish preparing the wood with a card scraper.

    I used General finishes Armor Seal poly for the attached piece. Four reasonably thin coats, sanding with 240 net in between coats. Then final coat and let dry for a few days, then sand with 800 net, and finally finish by rubbing out with 0000 steel wool and paste wax. The sheen is between satin and semigloss. You can check your sheen by reading the reflection of letters on a paint can or brochure (or whatever) placed at right angle to the surface. The clearer and easier to read, the closer to gloss (assuming you started with gloss.

    The hall table shows some reflection in this photo, although it was not taken for that purpose. The top is also smooth and slick enough that a microfiber cloth toss on it length ways will slide right off. Feels wonderful.
    (One more tip: if you have a drip on the surface, don't sand, use a well sharpened card scraper to plane the drip to completely level)

    Hope this helps.